core

### Variable Technique

Available for Linear Open, Linear Closed, Patch, Section, and Rotary scans

The VARIABLE technique in the scan dialog box (Insert | Scan) enables you to set specific maximum and minimum angle and increment values that will be used in determining where PC-DMIS will take a hit. The probe 's approach is perpendicular to the line between the last two measured hits.

Enter the maximum and minimum values that will be used to determine the increments between hits. You also must enter the desired values for the MAX and MIN angles. PC-DMIS will take three hits using the minimum increment. It will then measure the angle between hit's 1-2 and 2-3.

- If the measured angle is between the maximum and minimum values defined, PC-DMIS will continue to take hits at the current increment.

- If the angle is greater than the maximum value, PC-DMIS will erase the last hit and measure it again using one quarter of the current increment value.

- If the angle is less than the minimum increment, PC-DMIS will take the hit at the minimum increment value.

PC-DMIS will again measure the angle between the newest hit and the two previous hits. It will continue to erase the last hit and drop the increment value to one quarter of the increment until the measured angle is within the range defined, or the minimum value of the increment is reached.

- If the measured angle is less than the minimum angle, PC-DMIS doubles the increment for the next hit.

- If this is greater than the maximum increment value, it takes the hit at the maximum increment.

PC-DMIS again measures the angle between the newest hit and the two previous hits. It continues to double the increment value until the measured angle is within the range defined, or the maximum increment is reached.

If ANGLE > MAX ANG then INC = INC / 4 until MIN INC
If ANGLE < MIN ANG then INC = INC * 2 until MAX INC

Patch scans by default always start each new scan line with the minimum increment. If you would prefer that each new line start with the increment from the previously scanned line you can select the Patch Scans Maintain Last Increment check box on the General tab in the Setup Options dialog box (Edit | Preferences | Setup). For information, see "Patch Scans Maintain Last Increment" in the "Setting Your Preferences" chapter.